The NPD has been described as neo-Nazi by critics and accused of inciting hate crimes through its fiercely nationalist and anti-immigrant rhetoric. Members have also been accused of being linked to the National Socialist Underground, neo-Nazi terrorist organization, though the NPD has denied any affiliation.

There is concern among some German politicians that seeking to ban the NPD could strengthen it should the measure fail.

A previous attempt to ban the NPD in 2003 failed after the Federal Constitutional Court could not determine whether it was unconstitutional due to the presence of undercover government agents within the party’s ranks, arguing that they may have influenced the group to adopt unconstitutional policies.

Last month the NPD filed a case with the court to declare it constitutional, which has been viewed as an attempt to pre-empt a ban. No ruling has been made on the case.

A white Fiat van rammed into pedestrians outside enjoying a late afternoon stroll on Las Ramblas in Barcelona on Thursday killing at least 13 people and leaving hundreds injured. The Islamic State group claimed responsibility for the attack.